This application relates to the art of hinges, and more particularly related to a hinge which has a detent mechanism.
The hinge of the present invention is especially suited for use in a bi-fold or "accordian" door assembly. An accordian door assembly consists of one or more pairs of rectangular panels which are arranged to lie in a common plane when the door is closed. The adjacent or inner edges of the panels of each pair are hingedly connected to one another. The outer edge of each panel, remote from the hinged connection, is pivotally mounted to a track. At least one such outer edge of each pair of panels is also slidable with respect to the track.
Thus, the door may be opened by sliding the outer edges of each pair of panels toward one another, and folding the pair of panels against one another at their hinged connection. It is generally desirable to yieldably retain or "detent" the panels alternatively in the fully-opened or fully-closed positions. It is also desirable to provide a moderate frictional drag to resist movement of the panels over a range of positions between the fully-opened and fully-closed positions.
Hinges for use in accordian-type door assemblies must provide a multiplicity of features and must meet several stringent requirements.
Although the detent and frictional drag functions can be performed by structures other than the hinges, it is desirable to incorporate these functions in the hinges to minimize the cost and complexity of the assembly. However, in some cases, it will prove desirable to eliminate or disable the detent and drag mechanisms in one or more of the hinges in a particular assembly during installation. For example, if the panels of a particular assembly are especially long, and a large number of hinges will be used at each hinged connection between panels, then it may be desirable to eliminate the detent and drag functions from some of the hinges at each such connection to moderate the detent and drag forces in the assembly. Therefore, if the detent and frictional drag functions are incorporated in the hinge structure, the hinge should be designed so that these functions can be readily disabled or eliminated during installation.
A hinge for use in accordian-type door assemblies should also provide a positive stop to assure that, when the panels which the hinge connects are in the fully-closed position, they are precisely coplanar with one another. Preferably, the stop should be preset during manufacture of the hinge, so that its accuracy does not depend upon careful installation in the field.
Normally, at least two hinges will be used to connect each pair of panels in an accordian-type door assembly. To prevent binding and jamming of the panels, it is essential to accurately align all of the hinges which connect the same pair of panels so that the pivot axes of all of such hinges are coaxial with one another. Hinges for use in accordian-type door assemblies should, therefore, be constructed and arranged to minimize the care and skill required in installation to achieve such alignment.
The hinges in an accordian-type door assembly may be subjected to substantial forces due to the weight of the door panels and may also be subjected to additional substantial and unpredictable forces if the door assembly is abused. Therefore, hinges for use in such an assembly should be strong enough to resist such forces without damage. Further, such hinges should be constructed so that they may be mounted to the door panels in such a manner as to provide a strong connection between the hinges and the panels, even if the panels are formed from a relatively weak material such as particle board.
The hinges in a door assembly should last for the life of the door assembly and they should not require any maintenance during their lifetime. When the door assembly is painted, the hinges may be covered with a thick coating of paint. The hinges should continue to operate properly, and should continue to provide the aforementioned detent and drag functions, even after they have been covered with many coats of paint.
Because each accordian-type door assembly will normally include a substantial number of hinges, and a large number of door assemblies may be installed in a single building, the price of the hinges is of substantial importance. Therefore, hinges for this application must be manufacturable by the simplest possible methods from readily available materials.
Various hinge structures have been used in an accordian-type door assemblies. Most notably, the hinge structures set forth in U.S. Pat. Nos. 3,237,239 and 3,608,310, issued Mar. 1, 1966 and Sept. 28, 1971, respectively, to Jack Rudnick, have been widely adopted for this purpose. However, prior to the present invention, there has still been a need for a hinge which would better fulfill the aforementioned requirements.